This invention relates to a device for reducing data bandwidth for passing signals through a bandwidth restricting system and to do so without loss of data.
Present methods for passing data through bandwidth restricting systems involve ensemble sampling and data editing, both of which results in data loss. Manipulating bandwidth in time using deltics and memories results in extending the time required to pass the data, or increasing the bandwidth neither of which solve the basic problem. The invention relates to a bandwidth reduction device utilized in a sonobuoy system and more particularly to a device for generating subharmonics for reduction of bandwidth in which signals are divided in frequency for transmission and subsequently recreated into the original signal by a receiving station having a display means with X-axis calibrated for two times the bandwidth range. Techniques are now used for changing the frequency of sounds produced by musical instruments. For example, division of a fixed known frequency is accomplished by synchronizing a subharmonic oscillator with a known frequency to produce a subharmonic sinusoidal output. Another technique converts sinusoids into square waves at half the input frequency and then reconverts them into sinusoidals through tank circuit filtering. These techniques provide output tones that have an entirely different quality sounding completely different from those characterized by the original source. Additionally the original amplitude envelope is lost in the division of frequencies.